Bilateral reciprocal isokinetic exerciser

ABSTRACT

An Isokinetic Exerciser for exercising the limbs of a person bilaterally reciprocally includes an actuator means with simultaneous reciprocal force receiving input members on opposite ends of the actuator. A limb supporting lever is attached to each of the force receiving members. The actuator is coupled to a valve which adjustably controls the limit speed of rotation of the levers effectively independent of the forces applied thereto by controlling the flow of fluid through the valve.

tes atet 1 [11] 3,7843 Perrine Jan. 8, 1974 [54] BILATERAL RECHPROCALISOKHNETEC 3,465,592 9/1969 Pcrrinc 272/DlG. 6 EXERCHSER 3,495,8242/1970 Cuinier .0 272/79 C X 3,702,188 11/1972 Phillips et a1. 272/79 CX [76] Inventor: James .B. Pcrrine, 8973 Kobe PL,

San Dlego Calif 92123 Primary Examiner-Richard C. Pinkham [22] Filed:Apr. 20, 1972 Assistant Examiner-William R. Browne [21] App]. No.:245,742

[57] ABSTRACT 52 US. CH 272/79 C 272/5 0/545 R An Isokinetic Exerciserfor exercising the limbs Of a 272/DIG 4, 272/DIG 1 272/DIG 6 272/79person bilaterally reciprocally includes an actuator D means withsimultaneous reciprocal force receiving 51 im. Cl. A63b 23/04, A63b21/00 input members on Opposite ends of the actuatofl A [58] Field ofSearch 272/58 80, 54 79 G; limb supporting lever is attached to each ofthe force 60/545 91/186, 435 receiving members. The actuator is coupledto a valve which adjustably controls the limit speed of rotation of [56]References Cited the levers effectively independent of the forcesapplied thereto by controlling the flow of fluid through UNITED STATESPATENTS the valve- 2,903,263 9/1959 Ross 272/54 3,395,698 8/1968Morehouse 272/73 UX 12 Claims, 11 Drawing Figures PAIE'NTEDJAN 819M:siemsm SHUT 1 BF 5 sum 2 or 5 PATENTED 8 4 PATENnmm 8I974 saw u. (If 5I PATENTEIJ JAN 81974 SHEEI 5 BF 5 BIILATERAL RECIPIROCAL ISOKINETICEXERCISER This invention is directed at an isokinetic exerciser and morespecifically to a bilateral-reciprocal isokinetic exerciser.

My isokinetic exerciser disclosed in US. Pat. No. 3,465,592, describesan isokinetic apparatus of the type wherein a user moves one or botharms and legs together in the same direction against an accommodatingresistance at a controlled speed. By contrast, the present invention isdirected to an lsokinetic exerciser which provides for simultaneousbilateral-reciprocal movement of two limbs.

According to the invention there is provided an isokinetic bilateralreciprocal exercising device comprised of an actuator means withsimultaneous reciprocal motion inputs on opposite sides of the actuatorand a limb supporting lever is connected to each of the inputs. Theactuator incorporates control means for controlling the speed ofmovement and providing an accommodating resistance to the limbsupporting levers. In one embodiment the actuator may be a rotaryhydraulic actuator in which a rotor is driven via a gear train andattached levers by the leg movements of a user.

It is therefore the principal object of the present invention to providea bilateral-reciprocal isokinetic exerciser for exercising the upper orlower limbs in a simultaneously bilateral reciprocal movement patternagainst isokinetic loading.

It is another object of the present invention to provide abilateral-reciprocal isokinetic exerciser which will permit physicallyhandicapped patients to practice the coordinated bilateral-reciprocallower limb movements needed for efficient ambulation.

These and other objects and many of the attendant advantages of thisinvention will be readily appreciated as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings in which:

FIG. 1 is a perspective view of an exerciser device for exercising lowerlimbs of a seated patient, shown installed on a stand with a seat forthe patient;

FIG. 2 is an enlarged partially exploded perspective view of theactuator;

FIG. 3 is a right side elevational view of the device illustrated inFIG. 2;

FIG. 4 is a left side elevational view of the device illustrated in FIG.2;

FIG. 5 is an enlarged central vertical sectional view taken along line55 of FIG. 2;

FIG. 6 is a cross-sectional view taken along line 66 of FIG. 5;

FIG. 7 is a fragmentary sectional view taken along line 77 of FIG. 3;

FIG. 8 is a longitudinal sectional view taken through a control valvealong line 88 of FIG. 4;

FIG. 9 is a fragmentary vertical sectional view taken along line 9-9 ofFIG. 8;

FIG. 10 is an exploded perspective view of the control valve andassociated parts; and

FIG. 11 is a perspective view of another actuator used .with myexerciser device.

Referring, now to the drawings wherein like reference charactersdesignated like or corresponding parts throughout, there is illustratedin FIGS. 1 through 4 an exerciser device generally designated asreference numeral 20 mounted on a platform 22. The exerciser device 20includes an actuator housing 21 having two massive rectangular verticalside plates 24, 26 each of which is provided with a threaded bottom hole28 which receives a bolt 30 securing the exerciser 20 to the platform22. A threaded hole 32 (FIG. 4) in each upper end of the walls 24, 26defines a bolt (not shown) for securing a seat frame 34 to the top ofthe exerciser device 20. A seat 36 is mounted on the frame 34 by anyconventional well known fastener means. Secured to the frame 34 is abackrest 38 and a pair of lateral arms 40. A person using the exercisermay sit on the seat 36 and place each of his feet through a loop 41 of apedal 42 secured to a forward end 44a of an L-shaped lever 44, locatedon each side of the exerciser 20. The levers 44 turn in a vertical planeparallel to the plates 24, 26 and each of the levers have a shortinwardly turned arm 46 which terminates at the hub or flange 48 (FIG.2). In this embodiment, the hub or flange 48 is located at oppositesides of the exerciser 20, and each flange 48 provides a separate inputto the actuator housing 21. The hub or flange 48 may be selectivelybolted to gears (54, 56 and 58, 60) at opposite ends of the exerciser aswill thereinafter be more fully described.

A plurality of bolts 50 secured by nuts 51 extend through the plates 24,26 and hold them in abutment with opposite ends ofa cylindricalfluid-filled rotary actuator tube 52. At the outer side of the plate 24is a pair of mating spur gears 54, 56 which rotate in oppositedirections. At the outer side of the plate 26 is another pair of matingspur gears 58, 60 which rotate in the same direction with respect to oneanother.

Two valve assemblies generally designated as reference numberals 64 and66 extend between the plates 24, 26 and each has a control knob 68secured on a rotatable valve control shaft 72 which extends axially fromthe valve casing 74.

A fitting 76 is secured in a bore 80 and 82 with each fitting carrying aflexible tube 84 to provide communication between a pressure gauge 88and the interior of the valve assemblies 64 and 66. A fitting 92 in abore 94 at the top of the plate 26 carries a flexible tube 95 whichprovides communication between the interiors of the value casings 74 anda pipe 96 which is closed at the upper end by a cap 97 and is partiallyfilled with a fluid 98. The fluid 98 which may be a free flowing oilfills the tube 95, the tubes 84 and the interiors of the valves 64 and66 and the actuator tube 52. The tube 95 is attached to the lower end ofthe pipe 96 by a fitting 93.

The lower gears 56 and 60 rotate on respective shafts 102 journaled inbearings in the end plates 24, 26. The shafts 102 are axially alignedbetween the end walls 24, 26 by shaft 100. The upper gears 54 and 58 aresecured to opposite ends of a horizontal shaft 103 extending axially ofthe actuator tube 52 (see FIG. 5). The gears 54,56,58,60 are providedwith threaded holes 104 which receive bolts 106 by means of which themounting flanges 48 can be secured to selected gears at opposite ends ofthe exerciser device.

An idler gear 62 rotates on a fixed shaft bolted to the end wall 26, asbest viewed in FIGS. 3 and 7. Supporting a shaft 108 inside the actuatortube 52 are bushings 110 and 111 (FIGS. 5, 6) which are sealed byO-rings 112 in respective grooves 114. The periphery of the bushings110, 111 is enclosed by the actuator tube 52 and is sealed by O-rings113 to keep the fluid 98 inside the actuator tube 52. Within the shaft108 is a tie bolt 103 to which is attached the gear 58.

Mounted on the shaft 108 by a plurality of bolts 115 is a radiallyextending rotor 116 (FIG. 6) which is provided with seals 118 securedthereto at opposite faces of the rotor. The rotor seals 118 snugly fillthe actuator bore radially between the shaft 108 and the actuator tube52 and axially between the bushings 110 and 111. The rotor 116 can turnin either direction between opposite faces of a stator 120 which issecured by a plurality of bolts 122 to the inside of the actuator tube52. The shaft 108 clears the inner concave side of stator 120 which isprovided with seals 123 secured thereto at opposite faces thereof. Thestator seals 123 fill a space radially between the shaft 108 and theactuator tube 52 and axially between the bushings 110-and 111. The rotor116 and the stator 120 constitute movable and fixed partitionsrespectively which divide the interior of the actuator tube 52 into twochambers 125a and 1251) both of which are filled with the fluid 98. Apair of ports 126, 128 in the bushing 110 open into the chambers 125aand 1251) respectively and communicate with the bores 80, 82respectively in the end plate 24.

Both valve assemblies 64 and 66 are identical in con struction so adescription of one valve assembly will suffice for both. Reference isnow made to FIGS. 6, 8, 9 and wherein each valve assembly 64 and 66includes the cylindrical hollow stationary valve casing 74 in which issecured a cylindrical liner 149. The distal end of the casing 74 isclosed by a plug 150 which is secured in a hole 152 in the end plate 26by a plurality of bolts 153. The distal end of the valve casing 74 isseated in the hole 152 and is sealed by a gasket 155 and O-rings 145,and 147. A plurality of holes 156 are formed in the cylindrical liner149 of the valve casing 74 near its distal end (see FIGS. 8 and 10). Aplurality of slots 159 are formed in the valve casing 74 to expose holes156 which communicate with the vertical .bore 94 in the plate 26. Thedistal end of the valve casing 74 in hole 152 communicates with a pipe96 via the bore 94 the fitting 92 and the tube 95. The pipe 96 serves asan accumulator for the fluid 98 in a manner explained further below.

The proximal end of each valve casing 74 is set in a hole 160 in theplate 24, which is closed by a plug 162 and sealed by a gasket 164 at anabutment 165. Control rods or shafts 72 extend axially of the respectivevalve casings. An O-ring 163 seals the end of the valve casing at theabutment 165 in the plate 24. The shaft 72 carries a diametral cross pin166 at its inner end which is engaged in diametrically opposed slots 168formed in a cylindrical valve member 170. The valve member 170 has anopen proximal end and a wall 172 at the distal end of the valve memberwhich is formed with a crescent shaped hole 174; see FIGS. 8, 9, 10. Acoil spring 175 in the valve member 170 which is compressed between thepin 166 and the end wall 172 urges the valve member 170 into contactwith an apertured end wall 176 of another cylindrical valve member 180.The valve member 170 is freely rotatable whereas, the value member 180is movable axially but is held nonrotatably in the value casing. A pairof diametrically opposed slots 182 are formed in valve member 180. Afixed pin 184 extends diametrally 0f the valve casing through the slots182 and is seated in holes 185 in the cylindrical liner 149 of the valvecasing. The pin 184 prevents rotation of valve member 180 but permitsaxial movement of valve member 180, so that it can move under fluidpressure to the right as viewed in FIG. 8 for closing holes 156 andclosing off the interior of the valve casing from bore 94. A compressedcoil spring 186 in the valve member 180 is located between the pin 184and the end wall 176. This spring keeps valve member 180 retracted fromholes 156. End wall 176 has a crescent shaped hole 188 which canregister with the hole 174 in the end wall 172 of the valve member 170in one position of the valve member 170. By rotation of the valve member170 holes 174 and 188 can be overlapped or misaligned for partially orcompletely closing the passage for flow of fluid 98 between theinteriors of the two valve members 170 and 180. It will thus be apparentthat rotation of knob 68 and valve control shafts 72 can adjust the sizeof passage defined by the intersecting holes 174, 188 in the walls 172,176 for determining the rate of pressure compensates oil flow throughthe casings. The proximal ends of the valve casings are provided withprojections 190 by means of which the end of the valve casing is spacedfrom the annular abutment 165 extending across the hole 160 in the plate24. There is thus defined a passage between the interior ofeach valvecasing at its proximal end in the plate 24 and the bore or 82communicating with the nipple 76. In addition, the bore 80 communicateswith the hole 126 and the bore 82 communicates with the hole 128 in thebushing as hereinbefore mentioned.

It will now be apparent from an inspection of the drawings, that thegears 54, 58 and 60 rotate in one direction and that the gears 56 and 62rotate in a direction opposite thereto. By this arrangement, fourdifferent movements of the levers 44, 45 are possible as follows:

l. Coaxial, reciprocal movements in opposite directions-obtained byattaching the flange 48 to the axially aligned gears 56 and 60 atopposite ends of the exerciser device.

2. Coaxial, simultaneous in-line movements-obtained by attaching theflange 48 to the axially aligned gears 54 and 58.

3. Reciprocal movements in opposite directions on vertically spacedhorizontal axes-obtained by attaching the flange 48 to the axiallyspaced gears 56 and 58, or 56 and 54.

4. Simultaneous in-line movements on vertically spaced horizontalaxes-obtained by attaching the flange 48 to the axially spaced gears 54and 60.

The operation of the exerciser device will now be explained. Supposefirst for purposes of illustration, that flange 48 is attached to thegear 56 and 60 for reciprocal movements in opposite directions asindicated in arrangement No. 1 above. The person operating the devicesits on the seat 36 with his feet engaged in the loops 41 of the pedals42. The knob 68 is turned to overlap the holes 172, 188 in the valvemember 170, to any desired extent. The positions of the arrows on theknobs indicate the valve settings. The arrows might be set parallel toeach other so that both of the valve assemblies have substantially thesame setting. Now the person alternately extends one leg forcefullywhile the other leg rises automatically due to reciprocal movements ofthe levers. The speed with which the levers 44, 45 reciprocate isautomatically controlled by the apparatus. The control speed can only bechanged by turning the control shaft 72 to adjust the valve assemblies64, 66. The manner in which these automatic controls are effected willnow be explained.

Suppose the gear 56 moves clockwise as viewed in FIG. 6 to raise theattached lever 44 while the opposed gear 60 moves counterclockwise withthe shaft 108, and the rotor 116. This will cause a reduction of volumein the chamber 125a and an increase in the volume of the chamber 125b.The fluid 98 will be forced out of the chamber 125a through the hole 126in the bushing 110, and through the bore 80 to the proximal end of theupper valve casing 74 where the fluid 98 enters the casing 74 and passesthrough the valve members 170, and 180. At this point it will beunderstood that if the valve holes 174 and 188 are not at leastpartially overlapping, the passage for fluid will be closed and norotational movement of the gears and levers will be possible. The rateof fluid flow is determined by the size of the passage defined by theoverlapped holes 174, 188. From the valve member 180 in the upper casing74 the fluid flows through the holes 156 to the bore 94 and to the lowervalve casing 74. The fluid passes through the lower valve members 180and 170 in turn to the bore 82 and enters the chamber 125 through thehole 128 in the bearing plate 110. Varying the force applied to thepedals 42 cannot have any material effect in varying the speed ofmovement since this is primarily limited by the compensating action ofthe valve member 180. When a leg movement reaches the control speed, theresulting pressure drop across the orifice defined by overlapping holes174, 188 will cause the valve member 180 to move to the right as viewedin FIG. 8, to close a portion of the holes 156 and increase the fluidpressure thereby resisting acceleration of the gears and levers. Therestraining force acting on the pedals thus accommodates to effectivelymatch the force applied by the leg at the control speed.

When the rotor 116 reaches the stator 120, angular turning motion of thelevers is stopped. The lever 45 attached to the gear 60 is now raisedand reverse motion of the levers can not be effected. Now the rotor 116will turn clockwise as viewed in FIG. 6 to increase the volume ofchamber 125a and reduce the volume of chamber 125b.

It will be apparent that by setting the valve members in both valveassemblies to defined passages of equal size, the levers 44 and 45 willturn with substantially equal speed in both directions of movement. Ifthe passage in the upper valve assembly 64 is set larger than thepassage in the lower valve assembly, the lever 44 will move at a fasterspeed than the lever 45. In order to compensate for temperature changesand resulting expansion or contraction the fluid passes via the bore 94to the reservoir pipe 96 and the air chamber 99 alternately contractsand expands accordingly.

The same speed controls are effective when the flanges 48 are attachedto any other pair of gears listed above. When up and down simultaneousmovement of both the lever 44 and 45 is desired the flanges 48 will beattached to gears 54, 58 or 54, 60 as mentioned above. Then the patientor user may force both legs up and down simultaneously with the speedcontrolled by the valve settings as previously described. If desired, anattendant may manually raise the levers 44, 45 after they have beenfully lowered by the patient.

Referring now to FIG. 11 there is shown another actuator 200 supportedby the side walls 24, 26. Actuator 200 is a conventional cylinder 201having end plates 206 and a reciprocal piston 210 which divides thecylinder into two chambers. The piston 210 is connected via couplings209 to a plastic coated cable 202 which exits through each chamber fromthe cylinder 201 at each input end of the actuator 200. The cable 202travels around a pulley 204 and 205 where it is anchored by conventionalmeans (not illustrated). Each hub or flange 48 of the respectiveL-shaped levers 44, 45 is rigidly fixed to the side of one of thepulleys 205. The pulley 204 is journaled between the arms of a bracket203 and the pulley 205 is journaled on a shaft 207 which is fixed in therespective side wall 24, 26. The valve assemblies 64 and 66 extendbetween the side walls 24, 26 and communicate the fluid between theopposite chambers of the cylinder 201 internally within the assemblies64 and 66 and via external tubes (not shown) which are connected to theassemblies and the respective chambers. The valve assemblies 64 and 66function in the same fashion as previously described with respect to theactuator 21 and thus control the speed with which the levers 44, 45reciprocate.

While only two embodiments of the inventions have been illustrated anddescribed especially adapted for lower limb therapy it will be apparentthat many modifications and variations are possible. For example, thedevice may be mounted on other suitable housings. Moreover other typesof lsokinetic control actuators, i.e., hydraulic, electro-mecha'nical,centrifugal compensating brake, etc. may be used.

It should thus be understood that the foregoing relates to preferredembodiments of the invention and that they are intended to cover allchanges and modifications of the examples of the invention herein chosenfor the purposes of the disclosure, which do not consti tute departuresfrom the spirit and scope of the invention.

The invention claimed is:

1. An isokinetic bilateral reciprocal exerciser comprising an actuatormeans for transmission of forces exerted by a user, said actuator meanshaving two force receiving means, said actuator means having one of saidforce receiving means mounted at one end of said actuator means forapplying a users force so that when said latter mentioned forcereceiving means is moved in one direction a user's force will betransmitted to the opposite end of the actuator means to simultaneouslymove the other force receiving means mounted at the opposite end of theactuator means in an opposite direction, each of said force receivingmeans being movable through planes that are substantially parallel toeach other, and means for supporting both of said force receiving meansin spaced relationship to each other so that a user may position,respectively, each of his limbs simultaneously on both of said forcereceiving means during an exercise program,

a limb supporting lever means coupled to each of said force receivingmeans, means for receiving a force exerted by a user and an isokineticspeed controlling means connected to said actuator means for controllingthe speed of motion of said force receiving means effectivelyindependent of the force applied to said limb supporting lever meansonce the speed of motion of said force receiving means has reached apredetermined value.

2. An isokinetic bilateral reciprocal exerciser as defined in claim 1,further including means for adjustably setting said speed controllingmeans to obtain different selected control speeds of rotation of each ofsaid force receiving means.

3. An isokinetic bilateral reciprocal exerciser as defined in claim 1,wherein said actuator means include a first gear and a second gearaxially spaced from each other and meshed with each other at one end ofsaid actuator means, and a third gear, a fourth gear and a fifth geareach axially spaced from each other at the other end of said actuatormeans, said fifth gear being an idler gear meshed with said third gearand said fourth gear; and a rotatable shaft coupled to said first andthird gears in coaxial array at opposite ends of said actuator means,said second and said fourth gears being disposed in coaxial alignment,whereby said first and said second gears rotate in opposite directions,said second and said fourth gears rotate in opposite directions, andsaid first, said third, and said fourth gears rotate in the samedirection when a connection of said lever means between said second andsaid third gears effects coaxially rotation in opposite directions ofsaid spaced apart lever means and a connection of said lever means tosaid second and said fourth gears effects coaxial rotation of each ofsaid lever means in an opposite direction.

4. An isokinetic bilateral reciprocal exerciser as defined in claim 3,further including adjustment means for adjustably setting said speedcontrolling means to obtain different selected maximum speeds ofrotation of said gears and said lever means.

5. An isokinetic bilateral reciprocal exerciser as defined in claim 3wherein said lever means comprises a pair of levers;

a pair of apertured flanges, each of said levers, re-

spectively, secured to one of said apertured flanges for attachment toone of said gears at opposite ends of said actuator means; and

limb engaging means on said levers to keep a persons limbs engaged onsaid levers during movements thereof.

6. An isokinetic bilateral reciprocal exerciser as defined in claim 4,wherein said actuator means further includes a pair of spaced plates;

a cylinder secured between said plates;

said shaft extending axially through said cylinder;

a rotor secured to said shaft;

a stator secured to said cylinder end bushings closing opposite ends ofsaid cylinder; said rotor, said stator, said cylinder and said bushingsdefining two fluid filled chambers in said cylinder,

said plates being formed with ports communicating with said two chambersfor passing fluid out of one chamber and into the other chamber whensaid rotor rotates, and the speed of rotation of said gears beingcontrolled by the rate of flow of fluid passing between said chambers.

7. An isokinetic bilateral reciprocal exerciser as defined in claim 6,wherein said speed controlling means comprises a pair of fluid filledvalve assemblies having respectively, a casing communicating with saidports; said controlling means comprising an adjustment means forrotating a rotatable valve member adjacent a non-rotatable valve memberin each of said valve casings, said valve members having abutting wallswith adjustably overlapping holes defining a passage for fluid, and therate of flow of fluid and speed of rotation of said gears beingdetermined by the size of said passage.

8. An isokinetic bilateral reciprocal exerciser as defined in claim 7wherein said non-rotatable valve member is axially slidable against aspring bias, each of said valve casings having lateral holes closable bysaid nonrotatable axially slidable valve to limit flow of fluid andresist acceleration of rotation of said gears and said respectivelevers.

9. An isokinetic bilateral reciprocal exerciser as defined in claim 6,further comprising pressure indicating means operatively connected tosaid valve assemblies for indicating pressure of said fluid in saidvalve casings.

10. An isokinetic bilateral reciprocating exerciser as defined in claim8, further including an accumulator means partially filled with fluidand connected to said valve assemblies for relieving excess pressure dueto thermal expansion.

11. An isokinetic bilateral reciprocating exerciser as defined in claim1 wherein said actuator means comprises a cylinder;

a piston axially movable in said cylinder, and

a coupling means for connecting each side of said piston, respectivelyto each one of said limb supporting lever means.

12. An isokinetic bilateral reciprocating exerciser as defined in claim11 wherein said coupling means comprises a plastic coated cable.

1. An isokinetic bilateral reciprocal exerciser comprising an actuatormeans for transmission of forces exerted by a user, said actuator meanshaving two force receiving means, said actuator means having one of saidforce receiving means mounted at one end of said actuator means forapplying a user''s force so that when said latter mentioned forcereceiving means is moved in one direction a user''s force will betransmitted to the opposite end of the actuator means to simultaneouslymove the other force receiving means mounted at the opposite end of theactuator means in an opposite direction, each of said force receivingmeans being movable through planes that are substantially parallel toeach other, and means for supporting both of said force receiving meansin spaced relationship to each other so that a user may position,respectively, each of his limbs simultaneously on both of said forcereceiving means during an exercise program, a limb supporting levermeans coupled to each of said force receiving means, means for receivinga force exerted by a user and an isokinetic speed controlling meansconnected to said actuator means for controlling the speed of motion ofsaid force receiving means effectively independent of the force appliedto said limb supporting lever means once the speed of motion of saidforce receiving means has reached a predetermined value.
 2. Anisokinetic bilateral reciprocal exerciser as defined in claim 1, furtherincluding means for adjustably setting said speed controlling means toobtain different selected control speeds of rotation of each of saidforce receiving means.
 3. An isokinetic bilateral reciprocal exerciseras defined in claim 1, wherein said actuator means include a first gearand a second gear axially spaced from each other and meshed with eachother at one end of said actuator means, and a third gear, a fourth gearand a fifth gear each axially spaced from each other at the other end ofsaid actuator means, said fifth gear being an idler gear meshed withsaid third gear and said fourth gear; and a rotatable shaft coupled tosaid first and third gears in coaxial array at opposite ends of saidactuator means, said second and said fourth gears being disposed incoaxial alignment, whereby said first and said second gears rotate inopposite directions, said second and said fourth gears rotate inopposite directions, and said first, said third, and said fourth gearsrotate in the same direction when a connection of said lever meansbetween said second and said third gears effects coaxially rotation inopposite directions of said spaced apart lever means and a connection ofsaid lever means to said second and said fourth gears effects coaxialrotation of each of said lever means in an opposite direction.
 4. Anisokinetic bilateral reciprocal exerciser as defined in claim 3, furtherincluding adjustment means for adjustably setting said speed controllingmeans to obtain different selected maximum speeds of rotation of saidgears and said lever means.
 5. An isokinetic bilateral reciprocalexerciser as defined in claim 3 wherein said lever means comprises apair of levers; a pair of apertured flanges, each of said levers,respectively, secured to one of said apertured flanges for attachment toone of said gears at opposite ends of said actuator means; and limbengaging means on said levers to keep a person''s limbs engaged on saidlevers during movements thereof.
 6. An isokinetic bilateral reciprocalexerciser as defined in claim 4, wherein said actuator means furtherincludes a pair of spaced plates; a cylinder secured between saidplates; said shaft extending axially through said cylinder; a rotorsecured to said shaft; a stator secured to said cylinder end bushingsclosing opposite ends of said cylinder; said rotor, said stator, saidcylinder and said bushings defining two fluid filled chambers in saidcylinder, said plates being formed with ports communicating with saidtwo chambers for passing fluid out of one chamber and into the otherchamber when said rotor rotates, and the speed of rotation of said gearsbeing controlled by the rate of flow of fluid passing between saidchambers.
 7. An isokinetic bilateral reciprocal exerciser as defined inclaim 6, wherein said speed controlling means comprises a pair of fluidfilled valve assemblies having respectively, a casing communicating withsaid ports; said controlling means comprising an adjustment means forrotating a rotatable valve member adjacent a non-rotatable valve memberin each of said valve casings, said valve members having abutting wallswith adjustably overlapping holes defining a passage for fluid, and therate of flow of fluid and speed of rotation of said gears beingdetermined by the size of said passage.
 8. An isokinetic bilateralreciprocal exerciser as defined in claim 7 wherein said non-rotatablevalve member is axially slidable against a spring bias, each of saidvalve casings having lateral holes closable by said non-rotatableaxially slidable valve to limit flow of fluid and resist acceleration ofrotation of said gears and said respective levers.
 9. An isokineticbilateral reciprocal exerciser as defined in claim 6, further comprisingpressure indicating means operatively connected to said valve assembliesfor indicating pressure of said fluid in said valve casings.
 10. Anisokinetic bilateral reciprocating exerciser as defined in claim 8,further including an accumulator means partially filled with fluid andconnected to said valve assemblies for relieving excess pressure due tothermal expansion.
 11. An isokinetic bilateral reciprocating exerciseras defined in claim 1 wherein said actuator means comprises a cylinder;a piston axially movable in said cylinder, and a coupling means forconnecting each side of said piston, respectively to each one of saidlimb supporting lever means.
 12. An isokinetic bilateral reciprocatingexerciser as defined in claim 11 wherein said coupling means comprises aplastic coated cable.